The eXtremeDB runtime accesses the database through the binary form of the database schema called the Database Dictionary. This defines the data layout through which the C API functions then interact with the data storage. Some of the C API functions require the use of control structures and in some cases callback functions. Please use the following links for descriptions of these control structures and callback prototypes:
| Memory Devices | Logical Memory Devices |
| Database Parameters | Database open and runtime options |
| Log Parameters | Transaction Log file control |
| Runtime Info | Characteristics of the runtime currently active |
| Runtime Options | Options to control certain characteristics of the eXtremeDB runtime |
| Backup | Incremental Backup information |
| Disk Manager | Disk Manager and Cache control |
| Database Statistics | Memory usage statistics |
| Transaction | Database transaction control |
| Cursor | Cursor (for index searches) |
| Event Types | Database Event Types |
| Sequence_Iterator | The mco_seq_iterator_t structure used by the Analytics Functions that operate on database fields of type sequence |
| UDA | Uniform Data Access |
| XML Policy | XML Policy structure |
| Callback Functions | User-defined functions that are called by the eXtremeDB runtime |
| Transaction Logging | eXtremeDB Transaction Logging parameters |
| High Availability | eXtremeDB High Availability parameters |
| Cluster | eXtremeDB Cluster parameters |
| SSL Parameters | Secure Socket Layer parameters for network security |
| Socket Parameters | Socket parameters used for eXtremeDB network communications |
| Feed Handler | Feed Handler structures |
| Perfmon Database | The performance monitor database classes |
| Perfmon Options | The structure defining performance monitor database options |
| Tracing Framework | Tracing Framework Modules and Severity |
| EWS Web Server | The MCO EWS HTTP request structure |
| Web Services | The JSON structures used by the Web Services API |